MAX16992AUBB/V+ [MAXIM]
Switching Controller, Current-mode, 2500kHz Switching Freq-Max, BICMOS, PDSO10, UMAX-10;
| 型号： | MAX16992AUBB/V+ |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | Switching Controller, Current-mode, 2500kHz Switching Freq-Max, BICMOS, PDSO10, UMAX-10 信息通信管理 开关 光电二极管 |
| 文件： | 总19页 (文件大小：1248K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
EVALUATION KIT AVAILABLE
MAX16990/MAX16992
36V, 2.5MHz Automotive Boost/
SEPIC Controllers
General Description
Benefits and Features
● Minimized Radio Interference with 2.5MHz Switching
The MAX16990/MAX16992 are high-performance,
current-mode PWM controllers with 4μA (typ) shut-
down current for wide input voltage range boost/SEPIC
converters. The 4.5V to 36V input operating volt-
age range makes these devices ideal in automotive
applications such as for front-end “preboost” or “SEPIC”
power supplies and for the first boost stage in high-
power LED lighting applications. An internal low-dropout
regulator (PVL regulator) with a 5V output voltage
enables the MAX16990/MAX16992 to operate directly
from an automotive battery input. The input operating
range can be extended to as low as 2.5V when the
converter output is applied to the SUP input.
Frequency Above the AM Radio Band
● Space-Efficient Solution Design with Minimized
External Components
• 100kHz to 1MHz (MAX16990) and 1MHz to
2.5MHz (MAX16992) Switching-Frequency Ranges
• 12-Pin TQFN (3mm x 3mm) and 10-Pin μMAX
Packages
● Spread Spectrum Simplifies EMI Management Design
● Flexibility with Available Configurations for Boost,
SEPIC, and Multiphase Applications
• Adjustable Slope Compensation
• Current-Mode Control
• Internal Soft-Start (9ms)
There are multiple versions of the devices offering one
or more of the following functions: a synchronization
output (SYNCO) for two-phase operation, an overvoltage
protection function using a separate input pin (OVP), and
a reference input pin (REFIN) to allow on-the-fly output
voltage adjustment.
● Protection Features Support Robust Automotive
Applications
• Operating Voltage Range Down to 4.5V (2.5V or
Lower in Bootstrapped Mode), Immune to
Load-Dump Transient Voltages Up to 42V
• PGOOD Output and Hiccup Mode for Enhanced
System Protection
• Overtemperature Shutdown
• -40°C to +125°C Operation
The MAX16990 and MAX16992 operate in different
frequency ranges. All versions can be synchronized to
an external master clock using the FSET/SYNC input.
In addition, the MAX16990/MAX16992 have a factory-
programmable spread-spectrum option. Both devices
are available in compact 12-pin TQFN and 10-pin µMAX®
packages.
Typical Application Circuit
Applications
BOOTSTRAPPED 2.2MHz APPLICATION WITH LOW OPERATING VOLTAGE
22µF
● Automotive LED Lighting
● Automotive Audio/Navigation Systems
● Dashboards
0.47µH
P
BATTERY INPUT
2.5V to 40V
SW_OUT
8V/2A
47µF
CERAMIC
1µF
17kΩ
PVL
SUP
DRV
N
10kΩ
10kΩ
Ordering Information appears at end of data sheet.
91kΩ
1kΩ
PGOOD
PGOOD
N
ISNS
22mΩ
PVL
MAX16992AUBA/B
2.2µF
FB
FSET/SYNC
COMP
13kΩ
12kΩ
µMAX is a registered trademark of Maxim Integrated Products, Inc.
EN
N
GND
ENABLE
19-6632; Rev 7; 2/17
MAX16990/MAX16992
36V, 2.5MHz Automotive Boost/
SEPIC Controllers
Absolute Maximum Ratings
EN, SUP, OVP, FB to GND....................................-0.3V to +42V
DRV, SYNCO, FSET/SYNC, COMP,
PGOOD, ISNS, REFIN to GND............ -0.3V to (V
Operating Temperature Range........................ -40NC to +125NC
Maximum Junction Temperature.....................................+150NC
Storage Temperature Range............................ -65NC to +150NC
Lead Temperature (soldering, 10s) ................................+300NC
Soldering Temperature (reflow) ......................................+260NC
+ 0.3V)
PVL
PVL to GND............................................................... -0.3V to 6V
Continuous Power Dissipation (T = +70NC)
A
FMAX on SLB (derate 10.3mW/NC above +70NC).......825mW
FMAX on MLB (derate 12.9mW/NC above +70NC)....1031mW
TQFN on SLB (derate 13.2mW/NC above +70NC).....1053mW
TQFN on MLB (derate 14.7mW/NC above +70NC)....1176mW
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional opera-
tion of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect device reliability.
Package Thermal Characteristics (Note 1)
FMAX (Single-Layer Board)
Junction-to-Ambient Thermal Resistance (B ) ..........97NC/W
TQFN (Single-Layer Board)
Junction-to-Ambient Thermal Resistance (B ) ..........76NC/W
JA
JA
Junction-to-Case Thermal Resistance (B ).................5NC/W
Junction-to-Case Thermal Resistance (B )...................11NC/W
JC
JC
FMAX (Four-Layer Board)
TQFN (Four-Layer Board)
Junction-to-Ambient Thermal Resistance (B ) ..........78NC/W
Junction-to-Ambient Thermal Resistance (B ) ..........68NC/W
JA
JA
Junction-to-Case Thermal Resistance (B ).....................5NC/W
Junction-to-Case Thermal Resistance (B )...............11NC/W
JC
JC
Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer
board. For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial.
Electrical Characteristics
(V
= 14V, T = T = -40NC to +125NC, unless otherwise noted. Typical values are at T =+25NC.) (Note 2)
SUP
A
J
A
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
POWER SUPPLY
SUP Operating Supply Range
V
4.5
36
1.3
2
V
SUP
MAX16990
MAX16992
0.75
1.25
4
V
= 1.1V, no
FB
SUP Supply Current in Operation
I
mA
CC
switching
SUP Supply Current in Shutdown
OVP Threshold Voltage
I
V
= 0V
7
FA
SHDN
EN
% of
V
OVP rising
105
-1
110
2.5
115
OVP
V
FB
OVP Threshold Voltage
Hysteresis
% of
V
OVPH
V
FB
OVP Input Current
I
+1
FA
OVP
PVL REGULATOR
PVL Output Voltage
PVL Undervoltage Lockout
V
4.7
3.8
5
4
5.3
4.3
V
V
PVL
V
SUP rising
UV
PVL Undervoltage-Lockout
Hysteresis
V
0.4
V
UVH
Maxim Integrated
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MAX16990/MAX16992
36V, 2.5MHz Automotive Boost/
SEPIC Controllers
Electrical Characteristics (continued)
(V
= 14V, T = T = -40NC to +125NC, unless otherwise noted. Typical values are at T =+25NC.) (Note 2)
SUP
A
J
A
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
OSCILLATOR
R
R
= 69kI
= 12kI
360
400
440
FSET
Switching Frequency
f
kHz
SW
2000
2200
2400
FSET
Spread-Spectrum Spreading
Factor
% of
SS
B, D, and F versions
Q6
f
SW
MAX16990
MAX16992
MAX16990
MAX16992
100
1000
220
1000
2500
1000
2500
When set with
resistor on pin
Switching Frequency Range
FSET/SYNC Frequency Range
f
kHz
kHz
SWR
Using external
SYNC signal
f
SYNC
1000
FSET Regulation Voltage
Soft-Start Time
V
12kI < R
< 69kI
0.9
9
V
FSET
FSET
t
Internally set
6
12
ms
ms
SS
HICCUP
Hiccup Period
t
55
MAX16990, R
MAX16992, R
= 69kI
93
85
50
FSET
Maximum Duty Cycle
DC
%
MAX
= 12kI
FSET
Minimum On-Time
t
80
110
ns
ON
THERMAL SHUTDOWN
Thermal-Shutdown Temperature
Thermal-Shutdown Hysteresis
GATE DRIVERS
T
Temperature rising
165
10
NC
NC
S
T
H
I
I
DRV Pullup Resistance
DRV Pulldown Resistance
R
I
I
= 100mA
= -100mA
3
1.4
0.75
1
5.5
2.5
DRVH
DRV
DRV
R
DRVL
Sourcing, C
= 10nF
DRV
DRV Output Peak Current
I
A
DRV
Sinking, C
= 10nF
DRV
REGULATION/CURRENT SENSE
V
V
V
= VPVL
= 2V
0.99
1.98
0.495
-0.5
1
2
1.01
2.02
0.505
+0.5
288
REFIN
REFIN
REFIN
Across full line, load,
and temperature
range
FB Regulation Voltage
V
V
FB
= 0.5V
0.5
FB Input Current
ISNS Threshold
I
FA
FB
212
250
60
40
8
mV
MAX16990
MAX16992
ISNS Leading-Edge Blanking
Time
t
ns
BLANK
Current-Sense Gain
A
V/V
VI
Peak Slope Compensation
Current-Ramp Magnitude
Added to ISNS input
40
50
60
FA
Rising
Falling
85
80
90
85
95
90
Percentage of final
value
PGOOD Threshold
V
%
PG
Maxim Integrated
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MAX16990/MAX16992
36V, 2.5MHz Automotive Boost/
SEPIC Controllers
Electrical Characteristics (continued)
(V
= 14V, T = T = -40NC to +125NC, unless otherwise noted. Typical values are at T =+25NC.) (Note 2)
SUP
A
J
A
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
ERROR AMPLIFIER
REFIN Input Voltage Range
0.5
2
V
V
REFIN Threshold for 1V FB
Regulation
V
-
V
PVL
0.4
-
V
-
PVL
0.8
PVL
0.1
Error-Amplifier gm
A
700
FS
MI
VEA
Error-Amplifier Output
Impedance
R
50
OEA
COMP Output Current
I
140
3
μA
V
COMP
COMP Clamp Voltage
2.7
3.3
LOGIC-LEVEL INPUTS/OUTPUTS
PGOOD/SYNCO Output Leakage
Current
V
/V
= 5V
0.5
FA
PGOOD SYNCO
PGOOD/SYNCO Output Low
Level
Sinking 1mA
EN rising
0.4
1.2
V
EN High Input Threshold
1.7
2.5
-1
V
V
EN Low Input Threshold
FSET/SYNC High Input Threshold
FSET/SYNC Low Input Threshold
EN and REFIN Input Current
V
1
V
+1
FA
Note 2: All devices 100% production tested at T = +25NC. Limits over temperature are guaranteed by design.
A
Maxim Integrated
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MAX16990/MAX16992
36V, 2.5MHz Automotive Boost/
SEPIC Controllers
Typical Operating Characteristics
(V
= 14V, T = +25NC, unless otherwise noted.)
SUP
A
SHUTDOWN SUPPLY CURRENT
vs. SUPPLY VOLTAGE
SHUTDOWN SUPPLY CURRENT
SUPPLY CURRENT vs. SUPPLY VOLTAGE
vs. TEMPERATURE
10
5.2
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
9
8
7
5.0
4.8
4.6
4.4
4.2
4.0
3.8
2.2MHz
400kHz
6
5
4
3
3
2
1
0
V
V
= V
SUP
= 1.1V
EN
FB
V
= 0V
V
EN
= 0V
EN
3.6
4
12
20
28
36
-40 -20
0
20 40 60 80 100 120
TEMPERATURE (°C)
4
12
20
SUPPLY VOLTAGE (V)
28
36
SUPPLY VOLTAGE (V)
MAX16990 INTERNAL OSCILLATOR
FREQUENCY vs. SUPPLY VOLTAGE
PVL VOLTAGE vs. SUPPLY VOLTAGE
PVL VOLTAGE vs. SUPPLY VOLTAGE
5.2
5.1
5.0
4.9
4.8
4.7
4.6
4.5
4.4
4.3
4.2
4.1
4.0
5.2
5.0
4.8
4.6
4.4
4.2
4.0
3.8
3.6
3.4
3.2
3.0
410
408
406
404
402
400
398
396
394
392
390
I
= 1mA
PVL
I
= 1mA
PVL
I
= 10mA
PVL
I
= 10mA
PVL
R
= 68.1kI
SET
28
12
20
36
4
12
20
SUPPLY VOLTAGE (V)
28
36
3
4
5
6
7
4
SUPPLY VOLTAGE (V)
SUPPLY VOLTAGE (V)
MAX16990 INTERNAL OSCILLATOR
FREQUENCY vs. TEMPERATURE
MAX16992 INTERNAL OSCILLATOR
FREQUENCY vs. SUPPLY VOLTAGE
MAX16992 INTERNAL OSCILLATOR
FREQUENCY vs. TEMPERATURE
420
415
410
405
400
395
390
385
380
2400
2350
2300
2250
2200
2150
2100
2050
2000
2200
2190
2180
2170
2160
2150
2140
2130
2120
2110
2100
R
= 68.1kI
R
= 12.1kI
R
= 12.1kI
SET
SET
SET
28
-40 -20
0
20 40 60 80 100 120
TEMPERATURE (°C)
4
12
20
36
-40 -20
0
20 40 60 80 100 120
TEMPERATURE (°C)
SUPPLY VOLTAGE (V)
Maxim Integrated
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MAX16990/MAX16992
36V, 2.5MHz Automotive Boost/
SEPIC Controllers
Typical Operating Characteristics (continued)
(V
= 14V, T = +25NC, unless otherwise noted.)
SUP
A
POWER-UP RESPONSE
POWER-UP RESPONSE
MAX16990 toc10
MAX16990 toc11
5V/div
0V
5V/div
0V
V
V
V
SUP
OUT
SUP
5V/div
0V
5V/div
0V
V
V
OUT
DRV
5V/div
5V/div
0V
V
PVL
0V
5V/div
0V
5V/div
0V
V
V
PGOOD
PGOOD
2ms/div
2ms/div
STARTUP RESPONSE
STARTUP RESPONSE
MAX16990 toc12
MAX16990 toc13
5V/div
0V
5V/div
0V
V
V
V
SUP
OUT
PGOOD
5V/div
0V
5V/div
0V
5V/div
0V
V
V
OUT
DRV
V
PVL
5V/div
0V
5V/div
0V
5V/div
0V
V
EN
V
EN
2ms/div
2ms/div
STARTUP RESPONSE
(WITH SWITCHED OUTPUT)
OUTPUT LOAD TRANSIENT
MAX16990 toc15
MAX16990 toc14
5V/div
0V
5V/div
0V
V
SUP
V
PGOOD
5V/div
0V
5V/div
0V
5V/div
0V
V
V
OUT
OUT
V
OUT
500mV/div
(AC-COUPLED)
V
SW_OUT
5V/div
0V
V
EN
1A/div
I
LOAD
0A
50ms/div
2ms/div
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MAX16990/MAX16992
36V, 2.5MHz Automotive Boost/
SEPIC Controllers
Typical Operating Characteristics (continued)
(V
= 14V, T = +25NC, unless otherwise noted.)
SUP
A
LINE TRANSIENT
MAX16992 V
vs. V
SYNC SYNCO
MAX16990 toc16
MAX16990 toc17
5V/div
0V
V
V
V
SUP
OUT
OUT
2V/div
0V
V
SYNC
5V/div
0V
500mV/div
(AC-COUPLED)
2V/div
0V
V
SYNCO
1A/div
0A
I
LOAD
20ms/div
200ns/div
OUTPUT VOLTAGE vs. REFIN VOLTAGE
SWITCHING WAVEFORM
MAX16990 toc19
toc18
20
5V/div
V
OUT
0V
15
10
5V/div
0V
V
IN
5V/div
0V
V
LX
5
1A/div
0A
I
LOAD
IOU T = 0
0
500ns/div
0.5
1.0
1.5
2.0
REFIN VOLTAGE (V)
OVP SHUTDOWN
HICCUP MODE
MAX16990 toc20
MAX16990 toc21
V
OUT
5V/div
0V
V
V
OUT
DRV
5V/div
0V
1V/div
0V
V
V
OVP
DRV
5V/div
0V
5V/div
0V
V
PGOOD
5V/div
0V
5V/div
0V
V
PGOOD
1s/div
20ms/div
Maxim Integrated
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MAX16990/MAX16992
36V, 2.5MHz Automotive Boost/
SEPIC Controllers
Typical Operating Characteristics (continued)
(V
= 14V, T = +25NC, unless otherwise noted.)
SUP
A
MAX16992 INTERNAL OSCILLATOR
FREQUENCY vs. R
MAX16990 EFFICIENCY
MAX16992 EFFICIENCY
SET
2600
2400
2200
2000
1800
1600
1400
1200
1000
800
100
100
95
90
85
80
75
70
65
60
55
50
I
= 1A
95
90
85
80
75
70
65
60
55
50
OUT
I
= 2A
OUT
I
= 2A
OUT
I
= 1A
OUT
I
= 100mA
OUT
I
= 100mA
OUT
10
15
20
(kI)
25
30
4
5
6
7
8
4
5
6
7
8
R
SUPPLY VOLTAGE (V)
SUPPLY VOLTAGE (V)
SET
MAX16990 INTERNAL OSCILLATOR
FREQUENCY vs. RSET
CURRENT-LIMIT THRESHOLD
vs. TEMPERATURE
MAX16992 MAXIMUM DUTY
CYCLE vs. TEMPERATURE
MAX16990/2 toc25
260
258
256
254
252
250
248
246
244
242
240
91.0
90.5
90.0
89.5
89.0
88.5
88.0
87.5
87.0
1100
1000
900
800
700
600
500
400
300
200
100
0
R
= 12.1kI
SET
0
100
200
RSET(kΩ)
300
-40 -20
0
20 40 60 80 100 120
TEMPERATURE (°C)
-40 -20
0
20 40 60 80 100 120
TEMPERATURE (°C)
MAX16990 MAXIMUM DUTY
CYCLE vs. TEMPERATURE
COLD-CRANK INPUT VOLTAGE TRANSIENT
MAX16990 toc29
95.9
95.7
95.5
95.3
95.1
94.9
94.7
94.5
5V/div
V
IN
0V
5V/div
V
OUT
0V
1A/div
0A
5V/div
0V
I
LOAD
V
PGOOD
R
= 68.1kI
SET
-40 -20
0
20 40 60 80 100 120
TEMPERATURE (°C)
20ms/div
Maxim Integrated
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MAX16990/MAX16992
36V, 2.5MHz Automotive Boost/
SEPIC Controllers
Pin Configurations
TOP VIEW
TOP VIEW
TOP VIEW
9
8
7
9
8
7
+
SUP
EN
1
2
3
4
5
10
9
FB
FSET/SYNC 10
COMP 11
6
5
ISNS
PVL
FSET/SYNC 10
COMP 11
6
5
ISNS
PVL
MAX16990AUBA/B
MAX16992AUBA/B
COMP
FSET/SYNC
PGOOD
ISNS
MAX16990ATCC/D
MAX16992ATCC/D
MAX16990ATCE/F
MAX16992ATCE/F
GND
DRV
PVL
8
7
EP
FB 12
4
DRV
FB 12
4
DRV
EP
EP
6
+
+
1
2
3
1
2
3
µMAX
TQFN
(3mm x 3mm)
TQFN
(3mm x 3mm)
Pin Descriptions
MAX16990AUBA/B, MAX16990ATCC/D, MAX16990ATCE/F,
MAX16992AUBA/B MAX16992ATCC/D MAX16992ATCE/F
NAME
FUNCTION
μMAX-EP
TQFN-EP
TQFN-EP
Power-Supply Input. Place a bypass capacitor of at
least 1FF between this pin and ground.
1
1
1
SUP
Active-High Enable Input. This input is high-voltage
capable or can alternatively be driven from a logic-
level signal.
2
3
4
3
2
4
3
2
4
EN
GND
DRV
Ground Connection
Drive Output for Gate of nMOS Boost Switch. The
nominal voltage swing of this output is between PVL
and GND.
Output of 5V Internal Regulator. Connect a ceramic
capacitor of at least 2.2FF from this pin to ground,
placing it as close as possible to the pin.
5
6
5
6
5
6
PVL
Current-Sense Input to Regulator. Connect a sense
resistor between the source of the external switching
FET and GND. Then connect another resistor
between ISNS and the source of the FET for slope
compensation adjustment.
ISNS
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MAX16990/MAX16992
36V, 2.5MHz Automotive Boost/
SEPIC Controllers
Pin Descriptions (continued)
MAX16990AUBA/B, MAX16990ATCC/D, MAX16990ATCE/F,
MAX16992AUBA/B MAX16992ATCC/D MAX16992ATCE/F
NAME
FUNCTION
μMAX-EP
TQFN-EP
TQFN-EP
Open-Drain Synchronization Output. SYNCO outputs
a square-wave signal which is 180N out-of-phase
—
—
7
SYNCO with the device’s operational clock. Connect a pullup
resistor from this pin to PVL or to a 5V or lower
supply when used.
Overvoltage Protection Input. When this pin goes
above 110% of the FB regulation voltage, all
switching is disabled. Operation resumes normally
—
—
7
8
—
8
OVP
when OVP drops below 107.5% of the FB regulation
point. Connect a resistor divider between the output,
OVP, and GND to set the overvoltage protection
level.
Reference Input. When using the internal reference
connect REFIN to PVL. Otherwise, drive this pin with
an external voltage between 0.5V and 2V to set the
boost output voltage.
REFIN
Open-Drain Power-Good Output. Connect a resistor
from this pin to PVL or to another voltage less than or
equal to 5V. PGOOD goes high after soft-start when
the output exceeds 90% of its final value. When EN is
low PGOOD is also low. After soft-start is complete,
if PGOOD goes low and 16 consecutive current-limit
cycles occur, the devices enter hiccup mode and a
new soft-start is initiated after a delay of 44ms.
7
9
9
PGOOD
Frequency Set/Synchronization. To set a switching
frequency between 100kHz and 1000kHz
(MAX16990) or between 1000kHz and 2500kHz
(MAX16992), connect a resistor from this pin to
GND. To synchronize the converter, connect a logic
signal in the range 220kHz to 1000kHz (MAX16990)
or 1000kHz to 2500kHz (MAX16992) to this input.
The external n-channel MOSFET is turned on (i.e.,
DRV goes high) after a short delay (60ns for 2.2MHz
operation, 125ns for 400kHz) when SYNC transitions
low.
FSET/
SYNC
8
10
10
Output of Error Amplifier. Connect the compensation
network between COMP and GND.
9
11
12
11
12
COMP
FB
Boost Converter Feedback. This pin is regulated to
1V when REFIN is tied to PVL or otherwise regulated
to REFIN during boost operation. Connect a resistor
divider between the boost output, the FB pin and
GND to set the boost output voltage. In a two-phase
converter connect the FB pin of the slave IC to PVL.
10
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MAX16990/MAX16992
36V, 2.5MHz Automotive Boost/
SEPIC Controllers
Pin Descriptions (continued)
MAX16990AUBA/B, MAX16990ATCC/D, MAX16990ATCE/F,
MAX16992AUBA/B MAX16992ATCC/D MAX16992ATCE/F
NAME
FUNCTION
μMAX-EP
TQFN-EP
TQFN-EP
Exposed Pad. Internally connected to GND.
Connect to a large ground plane to maximize
thermal performance. Not intended as an electrical
connection point.
—
—
—
EP
Functional Diagram
5V REGULATOR
+ REFERENCE
SUP
PVL
(OVP)
UVLO
REF.
EN
EN
DRV
GND
THERMAL
THERMAL
50µA x f
SW
250mV
BLANKING
TIME
ISNS
CONTROL
LOGIC
FSET/SYNC
(SYNCO)
OSCILLATOR
8
PGOOD
COMP
FB
PGOOD
COMPARATOR
OTA
V
- 0.4V
PVL
MAX16990
MAX16992
1V
(REFIN)
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MAX16990/MAX16992
36V, 2.5MHz Automotive Boost/
SEPIC Controllers
Startup Operation/UVLO/EN
Detailed Description
The devices feature undervoltage lockout on the PVL-
regulator and turn on the converter once PVL rises
above 4V. The internal UVLO circuit has about 400mV
hysteresis to avoid chattering during turn-on. Once the
converter is operating and if SUP is fed from the output,
the converter input voltage can drop below 4.5V. This
feature allows operation at cold-crank voltages as low as
2.5V or even lower with careful selection of external com-
ponents. The EN input can be used to disable the device
and reduce the standby current to less than 4FA (typ).
The MAX16990/MAX16992 are high-performance,
current-mode PWM controllers for wide input voltage
range boost/SEPIC converters. The input operating volt-
age range of 4.5V to 36V makes these devices ideal in
automotive applications such as for front-end “preboost”
or “SEPIC” power supplies and for the first boost stage
in high-power LED lighting applications. An internal
low-dropout regulator (PVL regulator) with an output volt-
age of 5V enables the devices to operate directly from an
automotive battery input. The input operating range can
be as low as 2.5V when the converter output supplies
the SUP input.
Soft-Start
The devices are provided with an internal soft-start time
of 9ms. At startup, after voltage is applied and the UVLO
threshold is reached, the device enters soft-start. During
soft-start, the reference voltage ramps linearly to its final
value in 9ms.
The input undervoltage lockout (UVLO) circuit moni-
tors the PVL voltage and turns off the converter when
the voltage drops below 3.6V (typ). An external resistor
programs the switching frequency in two ranges from
100kHz to 1000kHz (MAX16990) or between 1000kHz
and 2500kHz (MAX16992). The FSET/SYNC input can
also be used for synchronization to an external clock. The
SYNC pulse width should be greater than 70ns.
Oscillator Frequency/External Synchronization/
Spread Spectrum
Use an external resistor at FSET/SYNC to program
the MAX16990 internal oscillator frequency from 100kHz
to 1MHz and the MAX16992 frequency between 1MHz
and 2.5MHz. See TOCs 24 and 25 in the Typical Operating
Characteristics section for resistor selection.
Inductor current information is obtained by means of an
external sense resistor connected from the source of the
external n-channel MOSFET to GND.
The devices include an internal transconductance error
amplifier with 1% accurate reference. At startup the
internal reference is ramped in a time of 9ms to obtain
soft-start.
The SYNCO output is a 180N phase-shifted version
of the internal clock and can be used to synchro-
nize other converters in the system or to implement a
two-phase boost converter with a second MAX16990/
MAX16992. The advantages of a two-phase boost topol-
ogy are lower input and output ripple and simpler thermal
managementasthepowerdissipationisspreadovermore
components. See the Multiphase Operation section for
further details.
The devices also include protection features such as
hiccup mode and thermal shutdown as well as an
optional overvoltage-detection circuit (OVP pin, C and D
versions).
Current-Mode Control Loop
The devices can be synchronized using an external
clock at the FSET/SYNC input. A falling clock edge on
FSET/SYNC turns on the external MOSFET by driving
DRV high after a short delay.
The MAX16990/MAX16992 offers peak current-mode
control operation for best load step performance and
simpler compensation. The inherent feed-forward
characteristic is useful especially in automotive appli-
cations where the input voltage changes quickly
during cold-crank and load dump conditions. While the
current-mode architecture offers many advantages, there
are some shortcomings. In high duty-cycle operation,
subharmonic oscillations can occur. To avoid this, the
device offers programmable slope compensation using
a single resistor between the ISNS pin and the current-
sense resistor. To avoid premature turn-off at the begin-
ning of the on-cycle the current-limit and PWM compara-
tor inputs have leading-edge blanking.
The B, D, and F versions of the devices have spread-
spectrum oscillators. In these parts the internal oscillator
frequency is varied dynamically 6% around the switch-
ing frequency. Spread spectrum can improve system
EMI performance by reducing the height of peaks due
to the switching frequency and its harmonics in the
spectrum. The SYNCO output includes spread-spectrum
modulation when the internal oscillator is used on the B,
D, and F versions. Spread spectrum is not active when
an external clock is applied to the FSET/SYNC pin.
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MAX16990/MAX16992
36V, 2.5MHz Automotive Boost/
SEPIC Controllers
n-Channel MOSFET Driver
device tries to restart by initiating a soft-start. Note that
a short-circuit on the output places considerable stress
on all the power components even with hiccup mode,
so that careful component selection is important if this
condition is encountered. For more complete protection
against output short-circuits, a series pMOS switch driven
from PGOOD through a level-shifter can be employed
(see Figure 1).
DRV drives the gate of an external n-channel MOSFET.
The driver is powered by the internal regulator (PVL),
which provides approximately 5V. This makes both the
devices suitable for use with logic-level MOSFETs. DRV
can source 750mA and sink 1000mA peak current.
The average current sourced by DRV depends on the
switching frequency and total gate charge of the external
MOSFET (see the Power Dissipation section).
Applications Information
Error Amplifier
Inductor Selection
Using the following equation, calculate the minimum
inductor value so that the converter remains in continu-
The devices include an internal transconductance error
amplifier. The noninverting input of the error amplifier is
connected to the internal 1V reference and feedback is
provided at the inverting input. High 700FS open-loop
transconductance and 50MΩ output impedance allow
good closed-loop bandwidth and transient response.
Moreover, the source and sink current capability of
140FA provides fast error correction during output load
transients.
ous mode operation at minimum output current (I
):
OMIN
2
L
= (V
x D x E)/(2 x f
x V
x I
)
MIN
IN
SW
OUT
OMIN
where:
D = (V
+ V - V )/(V
+ V - V
)
DS
OUT
D
IN
OUT
D
and:
I
is between 10% and 25% of I
OUT
OMIN
Slope Compensation
A higher value of I
however, it increases the peak and RMS currents in the
switching MOSFET and inductor. Select I between
10% to 25% of the full load current. V is the forward
voltage drop of the external Schottky diode, D is the duty
reduces the required inductance;
The devices use an internal current-ramp generator for
slope compensation. The internal ramp signal resets at
the beginning of each cycle and slews at a typical rate of
OMIN
OMIN
50FA x f . The amount of slope compensation needed
D
SW
depends on the slope of the current ramp in the inductor.
See the Current-Sense Resistor Selection and Setting
Slope Compensation section for further information.
cycle, and V
is the voltage drop across the external
DS
switch. Select an inductor with low DC resistance and
with a saturation current (I ) rating higher than the
SAT
Current Limit
peak switch current limit of the converter.
The current-sense resistor (R ) connected between the
source of the MOSFET and ground sets the current limit.
CS
Input and Output Capacitors
The input current to a boost converter is almost
continuous and the RMS ripple current at the input
capacitor is low. Calculate the minimum input capacitor
value and maximum ESR using the following equations:
The ISNS input has a voltage trip level (V ) of 250mV.
CS
When the voltage produced by the current in the induc-
tor exceeds the current-limit comparator threshold, the
MOSFET driver (DRV) quickly terminates the on-cycle.
In some cases, a short time-constant RC filter could be
required to filter out the leading-edge spike on the sense
waveform in addition to the internal blanking time. The
amplitude and width of the leading edge spike depends
on the gate capacitance, drain capacitance, and switch-
ing speed (MOSFET turn-on time).
C
IN
= DI x D/(4 x f
x DV )
SW Q
L
ESR
= DV /DI
ESR L
MAX
where DI = ((V - V ) x D)/(L x f ).
L
IN
DS
SW
V
is the total voltage drop across the external
DS
MOSFET plus the voltage drop across the inductor
ESR. DI is peak-to-peak inductor ripple current as
L
Hiccup Operation
calculated above. DV is the portion of input ripple due
Q
The devices incorporate a hiccup mode in an effort to
protect the external power components when there is
an output short-circuit. If PGOOD is low (i.e., the output
voltage is less than 85% of its set value) and there are
16 consecutive current-limit events, switching is stopped.
There is then a waiting period of 44ms before the
to the capacitor discharge and DV
is the contribution
ESR
due to ESR of the capacitor. Assume the input capacitor
ripple contribution due to ESR (DV ) and capacitor
ESR
discharge (DV ) are equal when using a combination of
Q
ceramic and aluminium capacitors. During the converter
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MAX16990/MAX16992
36V, 2.5MHz Automotive Boost/
SEPIC Controllers
INPUT
V
OUT
SUP
EN
DRV
N
ISNS
N
PVL
MAX16990
MAX16992AUBA
PVL
PGOOD
FB
FSET/SYNC
COMP
GND
Figure 1. Application with Output Short-Circuit Protection
turn-on, a large current is drawn from the input source
especially at high output to input differential. The devices
have an internal soft-start, however, a larger input capac-
itor than calculated above could be necessary to avoid
chattering due to finite hysteresis during turn-on.
minimum input voltage). Use a combination of low-ESR
ceramic and high-value, low-cost aluminium capacitors
for lower output ripple and noise.
Current-Sense Resistor Selection and Setting
Slope Compensation
In a boost converter, the output capacitor supplies the
load current when the main switch is on. The required
output capacitance is high, especially at lower duty
cycles. Also, the output capacitor ESR needs to be low
enough to minimize the voltage drop due to the ESR while
supporting the load current. Use the following equations
to calculate the output capacitor, for a specified output
ripple. All ripple values are peak-to-peak.
Set the current-limit threshold 20% higher than the peak
switch current at the rated output power and minimum
input voltage. Use the following equation to calculate an
initial value for R
:
CS
R
CS
= 0.2/{1.2 x [((V
x I
) x (V
)/E)/V
+ 0.5 x
x L))]}
OUT
OUT
INMIN
((V
– V
)/V
/(f
OUT
INMIN OUT
INMIN SW
where E is the estimated efficiency of the converter (use
0.85 as an initial value or consult the graph in the Typical
ESR = DV
/I
ESR OUT
Operating Characteristics section); V
the output voltage and current, respectively; V
and I
INMIN
is the switching
are
is the
OUT
OUT
C
OUT
= (I
x D
)/(DV x f
)
OUT
MAX
Q
SW
where I
is the output current, DV is the portion of the
Q
OUT
minimum value of the input voltage; f
SW
ripple due to the capacitor discharge, and DV
ripple contribution due to the ESR of the capacitor. D
is the maximum duty cycle (i.e., the duty cycle at the
is the
ESR
frequency; and L is the minimum value of the chosen
inductor.
MAX
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MAX16990/MAX16992
36V, 2.5MHz Automotive Boost/
SEPIC Controllers
The devices use an internal ramp generator for slope
compensation to stabilize the current loop when oper-
ating at duty cycles above 50%. The amount of slope
compensation required depends on the down-slope of
the inductor current when the main switch is off. The
inductor down-slope in turn depends on the input to out-
put voltage differential of the converter and the inductor
value. Theoretically, the compensation slope should be
equal to 50% of the inductor downslope; however, a
little higher than 50% slope is advised. Use the following
equation to calculate the required compensating slope
(mc) for the boost converter:
At high switching frequencies, dynamic characteristics
(parameters 1 and 2 of the above list) that predict switch-
ing losses have more impact on efficiency than R
),
DS(ON
which predicts DC losses. Qg includes all capacitances
associated with charging the gate. The V of the
DS(MAX)
selected MOSFET must be greater than the maximum
output voltage setting plus a diode drop (or the maximum
input voltage if greater) plus an additional margin to allow
for spikes at the MOSFET drain due to the inductance in
the rectifier diode and output capacitor path. In addition,
Qg determines the current needed to drive the gate at the
selected operating frequency via the PVL linear regulator
and thus determines the power dissipation of the IC (see
the Power Dissipation section).
mc = 0.5 x (V
– V )/L A/s
IN
OUT
The internal ramp signal resets at the beginning of each
cycle and slews at the rate of 50FA x f . Adjust the
Low-Voltage Operation
SW
amount of slope compensation by choosing R
satisfy the following equation:
to
SCOMP
The devices operate down to a voltage of 4.5V or less on
their SUP pins. If the system input voltage is lower than
this the circuit can be operated from its own output as
shown in the Typical Application Circuit. At very low input
voltages it is important to remember that input current will
be high and the power components (inductor, MOSFET
and diode) must be specified for this higher input current.
In addition, the current-limit of the devices must be set
high enough so that the limit is not reached during the on-
time of the MOSFET which would result in output power
limitation and eventually entering hiccup mode. Estimate
the maximum input current using the following equation:
R
= (mc x R )/(50e-6 x f
)
SCOMP
CS
SW
In some applications a filter could be needed between
the current-sense resistor and the ISNS pin to augment
the internal blanking time. Set the RC time constant just
long enough to suppress the leading edge spike of the
MOSFET current. For a given design, measure the lead-
ing spike at the lowest input and rated output load to
determine the value of the RC filter which can be formed
from the slope-compensation resistor and an added
capacitor from ISNS to GND.
I
= ((V
x I
)/V
)/E)/V
+ 0.5 x
INMAX
OUT
OUT
OUT
INMIN
MOSFET Selection
((V
– V
) x (V
/(f
x L))
INMIN OUT
INMIN SW
The devices drive a wide variety of logic-level n-channel
power MOSFETs. The best performance is achieved
with low-threshold n-channel MOSFETs that specify
where I
is the maximum input current; V
and
INMAX
OUT
I
are the output voltage and current, respectively;
OUT
E is the estimated efficiency (which is lower at low input
voltages due to higher resistive losses); V is the
on-resistance with a gate-source voltage (V ) of 5V or
GS
INMIN
less. When selecting the MOSFET, key parameters can
include:
minimum value of the input voltage; f
frequency; and L is the minimum value of the chosen
inductor.
is the switching
SW
1) Total gate charge (Q ).
g
2) Reverse-transfer capacitance or charge (C
).
RSS
Boost Converter Compensation
3) On-resistance (R
).
DS(ON)
Refer to Application Note 5587: Selecting External
Components and Compensation for Automotive Step-Up
DC-DC Regulator with Preboost Reference Design.
4) Maximum drain-to-source voltage (V
).
DS(MAX)
5) Maximumgatefrequenciesthresholdvoltage(V
).
TH(MAX)
SEPIC Operation
For a reference example of using the devices in SEPIC
mode, see Figure 2.
Maxim Integrated
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MAX16990/MAX16992
36V, 2.5MHz Automotive Boost/
SEPIC Controllers
22µF
1µF
33µF
27µH
5V/2A
BATTERY INPUT
2.5V-40V
24x7µF
CERAMIC
10µH
PVL
SUP
DRV
N
10kΩ
470Ω
12kΩ
PGOOD
ISNS
22mΩ
PVL
330pF
MAX16990AUBA
MAX16990AUBB
2.2µF
FB
FSET/SYNC
COMP
3kΩ
69kΩ
EN
N
GND
ENABLE
Figure 2. SEPIC Bootstrapped 400kHz Application with Low Operating Voltage
INPUT
V
OUT
SUP
DRV
N
ISNS
REFIN
MAX16990/2_ATC
PVL
OVP
FB
SYNCO
COMP
FSET/SYNC
EN
ENABLE
GND
Figure 3. Application with Independent Output Overvoltage Protection
Maxim Integrated
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MAX16990/MAX16992
36V, 2.5MHz Automotive Boost/
SEPIC Controllers
1µF
10µH
VIN
50V/1A
2x47µF
CERAMIC
22µF
SUP
DRV
N
FSET/SYNC
2200Ω
69kΩ
ISNS
MAX16992_ATC
20mΩ
PGOOD
PVL
FB
2.2µF
COMP
EN
SYNCO GND
10kΩ
10µH
22µF
1µF
FSET/
SYNC
SUP
DRV
N
75kΩ
2200Ω
ISNS
REFIN
20mΩ
MAX16992_ATC
PGOOD
1500Ω
PVL
2.2µF
COMP
SYNCO
FB
EN
N
GND
ENABLE
Figure 4. Two-Phase 400kHz Boost Application with Minimum Component Count
Overvoltage Protection
of the COMP signal and good current-sharing is attained
between the two phases. When designing the PCB for a
multiphase converter it is important to protect the COMP
trace in the layout from noisy signals by placing it on an
inner layer and surrounding it with ground traces.
The “C” and “D” variants of the devices include the over-
voltage protection input. When the OVP pin goes above
110% of the FB regulation voltage, all switching is dis-
abled. For an example application circuit, see Figure 3.
Using REFIN to Adjust the Output Voltage
Multiphase Operation
The REFIN pin can be used to directly adjust the
reference voltage of the boost converter, thus altering
the output voltage. When not used, REFIN should be
connected to PVL. Because REFIN is a high-impedance
pin, it is simple to drive it by means of an external digital-
to-analog converter (DAC) or a filtered PWM signal.
Two boost phases can be implemented with no extra
components using two ICs as shown in Figure 4. In this
circuit the SYNCO output of the master device drives the
SYNC input of the slave forcing it to operate 180N out-of-
phase. The FB pin of the slave device is connected to
PVL, thus disabling its error amplifier. In this way the error
amplifier of the master controls both devices by means
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MAX16990/MAX16992
36V, 2.5MHz Automotive Boost/
SEPIC Controllers
Power Dissipation
where V
is the voltage at the SUP pin of the IC, I
CC
SUP
is the IC quiescent current consumption or typically
0.75mA (MAX16990) or 1.25mA (MAX16992), Q is the
total gate charge of the chosen MOSFET at 5V, and f
SW
is the switching frequency. P reaches it maximum at
The power dissipation of the IC comes from two sources:
the current consumption of the IC itself and the current
required to drive the external MOSFET, of which the latter
is usually dominant. The total power dissipation can be
estimated using the following equation:
g
IC
maximum V
.
SUP
P
IC
= V
x I
+ (V
– 5) x (Q x f
)
SUP
CC
SUP
g
SW
Ordering Information
FREQUENCY
OVP/
SYNCO
SPREAD
SPECTRUM
PART
TEMP RANGE
PIN-PACKAGE
RANGE
MAX16990AUBA/V+
MAX16990AUBB/V+
MAX16990ATCC/V+
MAX16990ATCD/V+
MAX16990ATCE/V+
MAX16990ATCF/V+
MAX16992AUBA/V+
MAX16992AUBB/V+
MAX16992ATCC/V+
MAX16992ATCD/V+
MAX16992ATCE/V+
MAX16992ATCF/VY+**
220kHz to 1MHz
220kHz to 1MHz
220kHz to 1MHz
220kHz to 1MHz
220kHz to 1MHz
220kHz to 1MHz
1MHz to 2.5MHz
1MHz to 2.5MHz
1MHz to 2.5MHz
1MHz to 2.5MHz
1MHz to 2.5MHz
1MHz to 2.5MHz
None
None
Off
On
Off
On
Off
On
Off
On
Off
On
Off
On
-40NC to +125NC
-40NC to +125NC
-40NC to +125NC
-40NC to +125NC
-40NC to +125NC
-40NC to +125NC
-40NC to +125NC
-40NC to +125NC
-40NC to +125NC
-40NC to +125NC
-40NC to +125NC
-40NC to +125NC
10 FMAX-EP*
10 FMAX-EP*
12 TQFN-EP*
12 TQFN-EP*
12 TQFN-EP*
12 TQFN-EP*
10 FMAX-EP*
10 FMAX-EP*
12 TQFN-EP*
12 TQFN-EP*
12 TQFN-EP*
12 SWTQFN-EP*
OVP
OVP
SYNCO
SYNCO
None
None
OVP
OVP
SYNCO
SYNCO
/V denotes an automotive qualified part.
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad.
**Future product—contact factory for availability.
Chip Information
PROCESS: BiCMOS
Package Information
For the latest package outline information and land patterns (foot-
prints), go to www.maximintegrated.com/packages. Note that a
“+”, “#”, or “-” in the package code indicates RoHS status only.
Package drawings may show a different suffix character, but the
drawing pertains to the package regardless of RoHS status.
LAND
PATTERN
NO.
PACKAGE
TYPE
PKG
CODE
OUTLINE
NO.
12 SWTQFN-EP
12 TQFN-EP
10 FMAX-EP
T1233Y+4
T1233+4
U10E+3
21-100171
21-0136
90-100060
90-0019
21-0109
90-0148
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MAX16990/MAX16992
36V, 2.5MHz Automotive Boost/
SEPIC Controllers
Revision History
REVISION REVISION
PAGES
CHANGED
DESCRIPTION
NUMBER
DATE
3/13
4/13
4/13
7/13
2/15
7/15
8/15
0
1
2
3
4
5
6
Initial release
—
Added EP to μMAX package in Pin Description
9–11
7, 8
Corrected errors in TOCs 21 and 29
Removed future product asterisks from Ordering Information
Update the Benefits and Features section
18
1
Corrected value in Figure 2, changing inductor value from 22mF to 22mH
Corrected part number in Typical Application Circuit
16
1
Replaced toc18 in Typical Operating Characteristics, added MAX16992ATCF/VY+
in Ordering Information as a future product, and added SWTQFN-EP (package code
T1233Y+4) in Package Information sections
7
2/17
7, 18
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.
Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses
are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits)
shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.
©
Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.
2017 Maxim Integrated Products, Inc.
│ 19
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